Process of and apparatus for manufacturing metal dust



Jam 27., 1925 1,524,10T

M. H. NEWELL.

PROCESS OF AND APPARATUS FOR YMANUFACTURING METAL DUST Filed Sept. 13, 1921 2 sheets-sheet 1 Fig. l.

WITNESS INVENTOR ATTORNEYS 2? 11925. 1152mm M. H. NEWELL PROCESS OF AND APPARATUS FOR MANUFACTURING METAL DUST Filed Sept. 13. 1921 2 Sheets-Sheet 2 A} i L fig]:

WITNESS INVENTOR /7? A. MAW/M544 v 6M ATTORNEYS Patented Jan. 27, 1925.

UNITED ST TES.

. 1,524,1 01 PA NT oF'FlcB.

MINTON H. NEWELL, or sAN FRANCISCO, CALIFORNIA, ASSIGNOR TO THE ALLOYS co rANY, or sAN FRANCISCO, oALIroR- IA, A CORPORATION or CALIFORNIA.

PROCESS OF AND APPARATUS FOB. MANUFACTURING METAL DUST.

Application filed September T on whom it mag/concern I lie it known that I, MINTON II. Nnwnnn, a citizen of the United States, and a resident of the city and county of San Francisco, State of California, have invented a certain new and useful Process of and Apparatus for Manufacturing Metal Dust, of which the following is a specification.

The invention relates to a process of and an apparatus for manufacturing metal dust and particularly zinc dust. I 1

An object of the present invention is to provide a process of and an apparatus for manufacturing metal dust, particularly zinc dust, of extreme and uniform fineness.-

Another object of the invention is to provide an apparatus for maintaining the separation of and separately recovering the extremely fine metal dust and the larger particles of metal resultant from the condensation of metal vapor.-

A furtherfobject of the invention is to provide means for collecting and congre-f gating the coarser particles without admitting air to the condenser.

.The invention possesses other advantageous features, some of which, with the foregoing, will be set forth at length In the following description, where I shall outline in full, the process of my invention and that formof apparatus embodying my invention which I have selected for illustration in the drawings accompanying and forming part of the present specification. In said drawings I have shown one form of apparatus embodying my invention, but It is to be understood that I do not hmit myself to such form, since the inventioh, as set forth in the claims, may be embodied in plurality of forms. I A Referring, to said drawin s:

Figure 1 is a vertical section through one form of apparatus embodying my invention.

Fig. 2 is an elevation of the scraper mechanism, parts thereof being broken away to reduce the size of the figure.

Fig. 3 is a vertical section" through the scraper handle seal. f

In the manufacture of zinc dust, by the method which I employ, spelter, zinc dross or other zinc containing material, is heated to vaporization in a retort'and the vapors dischar ed into a condensing chamber in which t ey are condensed. The condenser- 13, 1921. Serial No. 500,369.

usually made of sheet metal and its outer surface 18 exposed to the air to permit the radiation of heat, and consequently the to produce zincdust. of extreme fineness,

I tllzltlllc vapor must be comparatively cool before it condenses or before it comes into contact with the cool walls of the condenser;

Some of the hot vapor however, contacts with the cool chamber walls before it becomes cool, with "the-result that metallic to the mouth of the retort than. in other por- ,tions of the condenser. The amount of metallic "droplets formed is reduced by shaping the condenser, with relation to the discharge outlet of the retort, so that the vapors are considerably cooled before they contact with the adjacent walls of the condenser,.but the formation of the metallic droplets in this region has not been entirely obviated. In accordance with my invention I collect these metallic droplets, or the major portion of them, separately from the larger portion of the'zinc dust and maintain this separation, so that the zinc dust is of uniformly extreme fineness. Some fine zinc dust is collected with the metallic droplets, but the main body of the fine zinc dust is practically free from the metallic droplets. The spelter, zinc dross or other zinc bearing material, is vaporized in a retort 2,

which is arranged within the furnace 3, the

neck 4 of the retort extending through and forming a tight joint with the front wall 5 of the furnace, to prevent "the entry of gases of combustion into the condenser. From the retort, which is preferably disposed in an inclined position, the hot zinc vapors discharge 7 into the condenser 6, through the hood 7, forming an'extension of the condenser and forming tight joints with the furnace walls. The condenser and the-hood are preferably formed of sheet metal, and the condenser is preferably cyline drical in shape and the hood is preferably rectangular its height being greater than its width. The mouth of the retort is arranged adjacent the bottom of the hood and the height of the hood is such that the top wall 78 thereof is spaced sufficiently from the month of the retort, to permit the hot Vapors from the mouth, to cool before they rise into contact with the top, to minimize the formation of droplets; The rear wall 9 of the hood is set back, preferably behind the plane of the front surface of the furnace. wall 5, to minimize the contact of the rising hot vapors therewith. The hood is preferably disposed adjacent the lower part of the condenser so that a clear condensing space is provided in the the condenser above the hood. V

The condenser is provided with a conical 7 bottom 13 in which the greater portion of the extremely fine zinc dust collects and at its lower end is provided with an inclined discharge chute 14, normally closed by the hinged gate 15. A separate receptacle is provided for collecting the metallic droplets mixed with whatever fine dust may deposit withthem and since these droplets form principally and almost entirely adjacent the mouth of the retort, or in the present construction, in the hood 7 this separate receptacle is arranged to receive and collect thematerial deposited in the hood. Disposed in. the conical bottom 13 on that side adjacent the hoodis a transverse inclined wall 16 which extends up to the hood and above the plane of the bottom wall ,17 thereof, forming with a portion of the conical bottom, a receptacle 18, separate from the [cone 13 andopening into the hood at the bottom thereof. -The receptacle 18 is provided at its lower end with a chute 19 passing vertically through the wall of the conical bottom, terminating at its lower end in an inclined portion 21 normally closed by the hinged gate 22. By virtue of the provision of two independent collecting chambers, the droplets are separately collected and the main body of the fine zinc dust is practically free from droplets."

The zinc vapor may be condensed in the presence of a limited or controlled amount of air or oxygen, introduced into the condenser MId filSt contacting with a comparatively cool portion of the vapor, and when air is to be admitted to the condenser it 'is provided at a point remote from the mouth of the retort, with a controllable aperture 23, through which air in, regulated quantity may be introduced, but when desired, this aperture maybe eliminated or closed and the condenser ractically sealed against the introduction'ofa ir. Whether the condenser densed in the hood 7 deposits on the bottom wall 17 thereof and means are provided for moving this deposited material into the receptacle 18. The means employed for this purpose is a scraper or hoe 24 provided with an operating handle 25 extending to the exterior of the condenser. The joint between thehandle and the wall of the condenser is sealed to prevent the inflow of air and the sealed joint is flexibly mounted to permit the handle to assume varying inclinations ,when the'scraper is operated. Secured'to the wall of the condenser opposite the retort, is a diaphragm or flexible disc 26 of impervious material, to the center of which is secured a stufling box 27 through which the liandle 25 passes. The handle is movable longitudinally through the stufiing box. the joint being sealed by the packing 28 and the stufiing box is flexibly mounted so that it is 9 free to assume various positions.

Means are provided for controlling the movement of the scraper, so that it will rise and pass over the material collected on the wall 17 on its back stroke, so that it will not. strike and injure the mouth of the retort and so that it will move horizontally over the wall 17 on its forward stroke, scraping the collected material into the receptacle 18. Pivoted to a bracket 31 secured to the wall 16 are a pair of parallel contiguous links 32, each provided with a longitudinal slot 33 terminatingat its end in a transverse pocket 34. The handle 25 of the scraper is provided with a cross pin 35 en agin in said slots, and movable into sai poc tets. Vh'en the scraper is in its foremost position, the links are forwardly inclined, as shown in full lines in Fig. 2 and the cross pin seats in the pockets 34. When the handle is pushed backward. the pin remains in the pockets, causing the links to rock on their pivots, moving the scraper through the curved path indicated by the dotted line, to

its rearward position, as shown. In this position, the links move to free the pin from the pockets, disposing itin the slots 33, so that on the forward movement of the ban .dle, the pin slides in the longitudinal slots and the scraper moves horizontally over the wall 17 scraping the material into the receptacle 18.

I claim:

1. The process of manufacturing metal dust, com rising vaporizin the metal, condensing t e vapor to meta dust and solid metallic droplets and collecting the metal dust separate from the droplets.

2. The process of manufacturing metal dust, comprising vaporizing the metal, in-

lilt) trdducing the vapor into a condensing chain- 10. An apparatus for manufacturing ber wherein it condenses to metal dust and metal dust comprising a retort in which the solid metallic droplets, collecting the dust metal is vaporized, an air cooled condensing separate from the droplets and separately chamber into which substantially all of the removing the dust from the condensing vapor is introduced and in which it conchamber; A denses to metal dust and solid metallic drop- 3. The process of manufacturing metal lets and means for collecting and recoverdust comprising vaporizing the meta1, coning the dust substantially free from densing the vapor in the presence of a droplets. limited regulated supply of oxygen, whereby 11. An apparatus for manufacturing metal dust and solid metallic droplets are metal dust comprising a retort in which the formed and collecting the metal dust free metal is vaporized, an air cooledcondensing from the droplets. chamber into which substantially all of the 4. The process of manufacturing metal vapor is introduced and inwhich it condenses dust, comprising vaporizing the metal, into metal dust and solid metallic droplets and troducing the vapor into a condenser Wheremeans for substantially separately collectin the hot vapor condenses to solid metallic ing the dust and the droplets.

droplets adjacent the vapor inlet and con- 12. An apparatus for manufacturingdenses to dust remote from the vapor inlet metal dust comprising a retort in which the and collecting and recovering the dust and metal is vaporized, an air cooled condensing thedroplets substantially separate. chamber into which substantially all of the 5 The process of manufacturing metal vapor is introduced andin which it condust, comprising vaporizing the metal, sup-' denses to metal dust and solid metallic droplying to the vapor a limited amount of air, lets, a large cone shaped bottom on the conrst contacting with a comparatively cool (lensing chamber'foiycollecting the dust and portion of the vapor, condensing the vapor a small collecting chamber for the droplets. in the presence of said supply of air where- 13. An apparatus for manufacturing by metal dust and metallic droplets are metal dust comprising a retort in which precipitated and collecting the dust subthe metal is vaporized, a condensing chamstantially separate from the droplets. her into which the vapor. is introduced and 6. The process of manufacturing metal in which it condenses to metal dust and dust, comprising vaporizing the metal, consolid metallic droplets, a collecting. chamdensing the vapor partly to metal dust and her for the dust, acollecting chamber for partlv to solid metallic droplets-and septhe droplets and separate gate controlled arately collecting and recovering the metal discharge apertures on said collecting chamdust substantially tree from droplets. bers, through which the collected material 7.. An apparatus for manufacturing metal may discharge by gravity,

dust comprising a retort in which the metal 14. An apparatus for manufacturing is p i a condensing chamber of heat metal dust comprising a retort in which'the conducting material into which substanmetal is vaporized, a condensing chamber in tially all of the vapor is introduced and which the vaporcondenses to metal dust, a

in which it condenses, a collecting chamber hood interposed between the retort and the ada ted to receive material condensed condensin chamber in which a ortion of adjacent the vapor inlet and a collecting th vap r condenses to metallic droplets, a chamber ad p ed o ce eria 00 collecting chamber for the dust, a collecting densed at other portions of the condensing chamber for the droplets and means for chamber whereby said materials are mainmoving the preciptated droplets into said tained separated. second collecting chamber. 8. An apparatus for manufacturingmetal 15. An apparatus for manufacturing dust comprising a retort in which the metal metal dust comprising a retort in which is vaporized, an air cooled condensing the metal is vaporized, a condensing chamber into which substantially all of the chamber in which the vapor condenses vapor is introduced and in which it conto metal dust, a hood interposed bedenses to metal dust and solid metallic drop tween the retort and the condensing lets and a collecting chamber for collectchamber in which avportion of the Va or ing the dust substantially separately from condenses to metallic droplets, a collecting the droplets. v chamberfor the dust, a collecting chamber 9. An apparatus for manufacturing metal for the droplets and a scraper operable from dust comprising a. retort in which the metal the exterior of the, condenser for moving the is vaporized, an air cooled con ensing precipitated droplets into said second colchamber into which substantially all of the lecting chamber. vapor is introduced and in which it con- 16. An apparatus for manufacturing densesto metal dust and solid metallic dropmetal dust'comprising a retort in which the lets, a collectingchamber for the dust and metal is vaporized, a condensing, chamber a collecting chamber for the droplets.

in which the vapor condensesto metal dust,

a hood interposedbetween the retort and the condensing chamber in which a portion of the va or condenses to metallic dro lets, a collecting chamber for the dust, a co lecting chamber for the dro lets, a scraper operable from the exterior o the condenser for moving the precipitated .droplets into said second collecting chamber and means for controlling7 the movement of said scraper. r 1 An apparatus for manufacturing metal dust comprising a retort in which the a metal is vaporized, .a condensing chamber in which the vapor condenses to metal dust, a hood interposed between the retort and the condensing chamber in which a portion of the vapor condenses to metallic dro lets,

a collecting chamber for the dust, a co lectr ing chamber for the droplets, a scraper operable from the exterior of the condenser for moving the precipitated droplets into said second collecting chamber and a flexible air-tight connection between the scraper and the wall of the condensing chamber. 1

18.,An' apparatus for manufacturing v metal dust comprising a retort in which the metal is vaporized, a condensing chamber in which the vapor condenses to metal dust,a

hood interposed between the'retort and the' condensing chamber in which a the vapor condenses to metallic ro lets, a collecting chamber for the dust, a co lecting chamber for the droplets, a scraper for moving the precipitated dro lets into said second collectin chamber, a andle on said box and a han 1e on carried by said diaphra rough said stufiing said scraper extending t box.

19. An apparatus for manufacturing metal dust comprising a retort in which the (portion of- ;scraper, a diap ragm disposed in the wall of the condensing chamber, a stu metal is vaporized, a condensing chamber in .movement of'the handle to move the scraper in a vertical arc.

ropletst into said 1 In testimony whereof,-.I have hereunto set my hand. I p

r mN'roN HFNEWELL. 

